A slightly different approach considers unequal error protection (UEP) to achieve reliability despite channel uncertainty.
This approach typically separates the source into a base layer and potentially multiple enhancement layers, with the base layer given the greatest amount of error protection to ensure a baseline reconstruction quality.
In [1]}, the source image is split into multiple layers in the discrete wavelet transform (DWT) domain before a quantizer and channel code is applied.
The bit rate allocation between the quantizer and channel code of each layer is optimized using an end-to-end rate distortion model.
Similarly, in [2]}, turbo codes [3]} and Reed-Solomon codes [4]} are used to achieve UEP.
In [5]}, instead of using different channel codes, the authors propose hierarchical modulation to achieve UEP.
However, none of these schemes were able to achieve adequate gains to justify the increase in system complexity stemming from the joint optimization of the parameters of multiple codes and the successive decoding needed at the receiver.
